The U.S. Pat. No. 7,022,996 B2 discloses a radiation detector that comprises a combination of a silicon (Si) and a CdZnTe (CZT) or CdTe conversion layer. With this configuration, low energy radiation is absorbed by the Si layer having superior resolution, while high-energy radiation is absorbed by the other layer having a high detection efficiency with respect to high energy radiation. This radiation detector is particularly suited for the detection of γ radiation with high energy resolution in the range of tens of eV.
Based on this situation it was an object of the present invention to provide alternative means for detecting radiation, particularly X- and γ-radiation, wherein it is desirable that these means can be applied in spectrally resolving imaging systems.
This object is achieved by a radiation detector according to claim 1, an X-ray detector according to claim 16, and an imaging system according to claim 17. Preferred embodiments are disclosed in the dependent claims.